Java線程死鎖代碼詳解

/**
 * @author hollis
 */
public class JStackDemo {
    public static void main(String[] args) {
        Thread t1 = new Thread(new DeadLockclass(true));//建立一個線程
        Thread t2 = new Thread(new DeadLockclass(false));//建立另一個線程
        t1.start();//啟動一個線程
        t2.start();//啟動另一個線程
    }
}
class DeadLockclass implements Runnable {
    public boolean falg;// 控制線程
    DeadLockclass(boolean falg) {
        this.falg = falg;
    }
    public void run() {
        /**
         * 如果falg的值為true則調用t1線程
         */
        if (falg) {
            while (true) {
                synchronized (Suo.o1) {
                    System.out.println("o1 " + Thread.currentThread().getName());
                    synchronized (Suo.o2) {
                        System.out.println("o2 " + Thread.currentThread().getName());
                    }
                }
            }
        }
        /**
         * 如果falg的值為false則調用t2線程
         */
        else {
            while (true) {
                synchronized (Suo.o2) {
                    System.out.println("o2 " + Thread.currentThread().getName());
                    synchronized (Suo.o1) {
                        System.out.println("o1 " + Thread.currentThread().getName());
                    }
                }
            }
        }
    }
}

class Suo {
    static Object o1 = new Object();
    static Object o2 = new Object();
}

import org.springframework.stereotype.Component;


@Component
public class SynchronizedTest {

      private static final Object lockA = new Object();
      private static final Object lockB = new Object();

      
      
      /**
       * ThreadA先獲取lockA,在獲取lockB
       */
      private static class ThreadA extends java.lang.Thread {

        @Override
        public void run() {
          // 獲取臨界區A
          synchronized (lockA) {
            System.out.println("get lockA success");
            // 模擬耗時操作
            try {
                Thread.currentThread().setName("線程A");
              Thread.sleep(500);
            } catch (InterruptedException e) {
              e.printStackTrace();
            }
            // 獲取臨界區B
            synchronized (lockB) {
              System.out.println("get lockB success");
            }
          }
        }
      }

      /**
       * ThreadB先獲取lockB,在獲取lockA
       */
      private static class ThreadB extends java.lang.Thread {

        @Override
        public void run() {
          // 獲取臨界區A
          synchronized (lockB) {
            System.out.println("get lockB success");
            // 模擬耗時操作
            try {
                Thread.currentThread().setName("線程B");
              Thread.sleep(500);
            } catch (InterruptedException e) {
              e.printStackTrace();
            }
            // 獲取臨界區B
            synchronized (lockA) {
              System.out.println("get lockA success");
            }
          }
        }
      }
      
      static {
          new ThreadA().start();
          new ThreadB().start();
      }
    }